1. Field of the Invention
The present invention relates to systems, devices, and methods for measuring pressure. More particularly, the present invention relates to systems, devices, and methods for measuring intraocular pressure.
2. Background Art
Devices that measure intraocular pressure (IOP) by measuring the applanation of the cornea are known in the art. Ophthalmologists use such devices to measure IOP in a physician's office. However, these single-point measurements remain insufficient to fully manage eye disease, particularly glaucoma. IOP peaks are missed in office hours measurements, IOP fluctuations may be an independent risk factor, and a majority of glaucoma patients require changes to their topical and/or surgical management approach after multiple IOP measurements on a single day. Infrequent measurements also make it difficult to evaluate treatment effectiveness and/or to assess patient compliance. However, more frequent, longer term tonometry is labor intensive, impractical, expensive, and often conducted only upon admission to an academic hospital. Tonometers that can be used by the patient are know in the art, but these devices often cause discomfort, have proven difficult for patients to repeatably administer, and have demonstrated unacceptable error in clinical studies.
Implantable electronic devices for more frequent measurement of intraocular pressure are known in the art. Readout of passive electronic sensors has proven problematic because inductively coupling to tiny receivers in the sensor is difficult. Active sensors overcome this problem, but require implantable power sources or power storage systems, implanted integrated circuits, and large antennas. As a result, both passive and active systems have so far proven too large and complex, mostly irreversible, risky with regard to biocompatibility, and/or error prone.